Epoxy Adhesive Formulations
Based on a popular course sponsored by the Society of Plastics Engineers, this comprehensive text presents a variety of methods to ensure optimum epoxy performance and reliability.
TABLE OF CONTENTS Epoxy Adhesive Formulations
Chapter 4: Epoxy Resins
4.1 INTRODUCTION
The syntheses of commercial epoxy resins that are commonly used in many applications were discussed in Chap. 2. Additional information is provided in this chapter with regard to the physical and chemical properties of certain epoxy resins relative to their use in adhesive systems.
Many types of epoxy resins can be used in adhesive formulations. These are characterized in Table 4.1. The most commonly used type is the resin-based diglycidyl ether of bisphenol A (DGEBA). Epoxy novolac, flexible epoxy, high-functionality, and film-forming epoxy resins are also used in specialty applications.
| Epoxy resin type | Characteristics | Primary curing requirements [*] |
|---|---|---|
| Diglycidyl ether of bisphenol A (DGEBA) | General-purpose use | RT, ET |
| Bisphenol F diluted DGEBA | Very low viscosity | RT, ET |
| Epoxy novolac | High heat and chemical resistance | ET |
| Flexibilizing | High elongation and impact resistance | RT, ET |
| Brominated DGEBA | Flame resistance | RT, ET |
| Aliphatic | High reactivity and low viscosity | RT, ET |
| Cycloaliphatic | Good electrical characteristics and chemical resistance, low viscosity | ET |
| High functionality | High heat and chemical resistance | ET |
| Film formers | Adhesion promotion, high resiliency | RT, ET |
| [*]RT = room temperature, ET = elevated temperature. |
The epoxy resin is a primary component in any epoxy adhesive formulation, and it is often referred to as the base polymer. However, it is certainly not the only or even not always the predominant component in influencing desirable end properties. Epoxy resins by themselves are often too rigid to provide the required properties such as flexibility, peel and impact...
Copyright The McGraw-Hill Companies, Inc. 2006 under license agreement with Books24x7
